There was a very very long comment thread on Reddit about how 50 Shades of Grey came about, spearheaded by someone who witnessed it happen in real time. Basically, it was originally a Twilight fanfic involving no vampires (which is apparently not unusual). EL James wasn't an involved member of the fanfic community, but she was very shrewd, and took note of what made the most popular fanfics so popular. And then she wrote 50 Shades of Grey to contain basically ALL of the popular tropes and formulas that she saw. It was literally written to be viral.
She was also shrewd enough to publish it in short chapters, to maximize the amount of views she got. So that's why it got up to the most hits on the fanfic website, and she managed to get it published touting those elevated numbers. Then she marketed it to the fanfic website, saying they should support one of their own, etc.
Then when she hit it big, she deleted everything she had on the fanfic website, deleted her account, cut off contact with all of her followers there, and basically pretended they never existed at all.
If anything, I have to admire how utterly shrewd she is. But she is no talented writer, she doesn't care about how her work affects others, and she certainly doesn't care if her portrayal of BDSM is accurate or not. From what I gathered, all she wants is to make money.
If anyone wants to read 50 Shades of Grey, they should go right ahead. IMO, if someone really learns that an abusive relationship is a healthy one because of what they read in a couple books, they were clueless and insecure to begin with.
I've read a couple paragraphs. It was utter s***, so I stopped.

Nobody says you have to read the whole book to make a quality judgement call.